This is where I like Gran Turismo Sport’s system:
https://www.gran-turismo.com/us/gtsport/manual/#!/sportmode/content03
You had 3 events, that’s it. Not 3 events per playlist, 3 playlists period. Initially, the track in each playlist didn’t even change, though the playlists changed daily.
They ran every 20 minutes (if I remember correctly). There was zero overlap in an individual playlist, only between playlists as a whole.
This hyperfocuses players into specific races, leads to bigger grids and better matchmaking.
Importantly however, searchable custom lobbies were still there for people who don’t find the current official races appealing. That way everybody has something they can race in.
At the moment Forza Motorsport has 11 active playlists (including Qualifier Series), and overlapping races in each. This is in a game that feels like it has far fewer concurrent players online than GT or F1.
To fill each of these rooms you need 264 people to be seeking races at the same time, and for them to be evenly spread across all rooms. Double that because we know some playlists are more popular than others. Now multiply that by 6, to get an even split across all Safety Ratings, then multiply it by 5 to get a good spread across all Driver Ratings.
So, to fill up every active playlist in Forza Motorsport with (a) full lobbies, (b) with good skill balance and (c) with good safety balance, you need over 15,840 people online at the same time, all searching for a race within the same 15-20 minute window.
Here is how many people are playing on Steam, you can probably 5x or 10x that when you factor in console and Game Pass: https://steamdb.info/app/2440510/charts/
This game cannot sustain the number of active events in Featured Multiplayer right now. This is why many races feel “dead”, the few players this game has have too many choices in what to race.